Problem: Tiffany ate 4 slices of cake. Luis ate 1 slice. If there were initially 9 slices, what fraction of the cake is remaining?
Solution: $\text{fraction of cake eaten} = \dfrac{\text{number of slices remaining}}{\text{number of slices total}}$ Together they ate 5 slices, which leaves 4 out of 9 slices remaining. There is $\dfrac{4}{9}$ of the cake remaining.